SCIENCE OF THE TOTAL ENVIRONMENT
·
2025
·
IF 8
Shuangmei Liu,Siqi Liu,Jiawei Wang,Jiangwei Ren,Yongxiang Li,Hui Mao
The presence of metronidazole (MNZ) in medical wastewater poses a potential threat to environmental safety and people's health. Herein, we report an innovative strategy to fabricate a recyclable bayberry tannin (BT)-functionalized melamine foam (MF)-supported nanoscale zero-valent iron (MFBT-Fe 0 ) catalyst for efficient MNZ degradation in medical wastewater. The through-pore structure of MF reduced mass transfer resistance in heterogeneous systems, while the amphiphilic BT stabilized nZVI via steric hindrance and chelating interactions and created a high-concentration MNZ microenvironment through hydrophobic combined with hydrogen bonding. The synergistic design overcame the long-standing challenges of mass transfer limitations in heterogeneous systems, nZVI aggregation- and shedding-mediated activity degradation, and the establishment of high-concentration microenvironments for MNZ reductive transformation. Consequently, the highly accessible nZVI catalyst, MFBT-Fe 0 , rapidly removed MNZ, achieving a 96.4 ± 0.82 % removal rate within 90 min, with a degradation capability 2.9-fold higher than the non-BT-functionalized MF-Fe 0 . MFBT-Fe 0 exhibited exceptional cycle stability, maintaining an MNZ removal rate of up to 80 % after 6th cycles. Mechanistic studies revealed contributions from surface complexation, hydrogen bonding, and π-π stacking, with HPLC-MS confirming degradation pathways of nitro reduction, denitrification and hydroxyethyl cleavage. This work provides a sustainable, high-performance catalyst for practical MNZ removal, addressing both efficiency and recyclability challenges in medical wastewater treatment.
研究领域:
环境科学
·
化学工程
·
催化
·
水处理
·
纳米技术
·
绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Jianzheng Yang,Hua Tian,Jianrong Guo,Junhui He
Overcoming the instability and poor recyclability during the practical applications of contaminant scavengers is a challenging topic. Herein, a three-dimensional (3D) interconnected carbon aerogel (nZVI@Fe 2 O 3 /PC) embedding a core-shell nanostructure of nZVI@Fe 2 O 3 was elaborately designed and fabricated via an in-situ self-assembly process. The porous carbon with 3D network architecture exhibits strong adsorption towards various antibiotic contaminants in water, where the stably embedded nZVI@Fe 2 O 3 nanoparticles not only serve as magnetic seeds for recycling, but also avoid the shedding and oxidation of nZVI in the adsorption process. As a result, nZVI@Fe 2 O 3 /PC efficiently captures sulfamethoxazole (SMX), sulfamethazine (SMZ), ciprofloxacin (CIP), tetracycline (TC) and other antibiotics in water. In particular, an excellent adsorptive removal capacity of 329 mg g −1 and a rapid capture kinetics (99% of removal efficiency in 10 min) under a wide pH adaptability (2–8) are achieved using nZVI@Fe 2 O 3 /PC as an SMX scavenger. nZVI@Fe 2 O 3 /PC displays exceptional long-term stability given that it shows excellent magnetic property after it is stored in water solution for 60 d, making it an ideal stable scavenger for contaminants in an etching-resistant and efficient manner. This work would also provide a general strategy to develop other stable iron-based functional architectures for efficient catalytic degradation, energy conversion and biomedicine.
研究领域:
环境科学
·
材料科学
·
纳米技术
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Song Li,Di Feng,Juncheng Liu,Qinglong Liu,Jingchun Tang
The reduction process of pollutants by nano zero-valent iron (nZVI) is limited by mass transfer and its effective utilization, and previous studies have ignored the electron loss caused by its oxidative passivation. The carbon-coated structure can effectively inhibit the oxidation of nZVI, but the effectiveness of carbon-coated nZVI (Fe 0 @C) as a reducing agent in soil remediation is unclear. Therefore, in this study, the Fe 0 @C/surfactant system was used to remove soil-adsorbed nitrobenzene (NB) to simultaneously enhance the mass transfer process and effective utilization of nZVI. The results showed that the use of surfactants effectively promoted the desorption of NB adsorbed by the soil, and the desorption process was affected by factors such as the type and concentration of surfactants, water-soil ratio, and soil organic matter (SOM) content. The enhanced desorption of NB by the surfactant in the soil system promoted the effective contact between the composite and NB, thereby enhancing the reduction of NB by the composite. In addition, Fe 0 @C exhibited excellent performance for the reduction of soil-adsorbed NB compared with the conventional nZVI, and this advantage was more obvious in the potting soil system. However, the composite will be gradually passivated due to the alkaline environment during the reduction process, and this phenomenon was especially obvious in the campus soil system. When the pH value decreased from 9 to 3, the proportion of aniline (AN) generated in the campus soil system increased from 19.37 % to 69.29 %. In addition, in potting soil systems with high SOM content, the adsorption of soil particles to the composite and the high dissolved organic matter (DOM) content resulting from the high SOM content also negatively affected the reduction process. The conclusions of this study demonstrate the great potential of the Fe 0 @C/surfactant system for in-situ contaminated site remediation applications.
研究领域:
环境科学
·
化学工程
·
土壤化学
·
污染物修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2016
·Vol. 43
·期 5
·3219-3236
·
IF 1.833
Farooq Usman,Danish Muhammad,Lu Shuguang,Naqvi Muhammmad,Gu Xiaogang,Fu Xiaro,Zhang Xiang,Nasir Muhammad
Graphene-oxide-supported nano zero-valent iron (nZVI) composite (nZVI–rGO) was synthesized and tested as an efficient percarbonate activator for degradation of 1,1,1-trichloroethane (TCA). Significant dispersion of nZVI on the surface of reduced graphene oxide (rGO) was observed, with good limitation of nanoparticle agglomeration and aggregation. Good TCA degradation efficiency of 90% was achieved in 2.5 h in presence of 0.8 g/l nZVI–rGO catalyst and 30 mM sodium percarbonate (SPC) oxidant; however, excessive catalyst or oxidant concentration reduced the degradation efficiency. Investigation of reactive oxygen species using radical probe compounds as well as radical scavengers confirmed presence of hydroxyl (OH · ) and superoxide ( \({\text{O}}_{2}^{\cdot - }\) ) radicals that are responsible for the TCA degradation. The morphology and surface characteristics of the heterogeneous catalyst were analyzed by transmission electron microscopy and scanning electron microscopy. Brunauer–Emmett–Teller analysis revealed that the synthesized catalyst had large surface area and small particle size of 299.12 m 2 /g and 20.10 nm, respectively, compared with 5.33 m 2 /g and 1.12 µm for bare graphene oxide. X-ray diffraction analysis revealed good dispersion of nZVI on the surface of rGO. Fourier-transform infrared characteristic peaks confirmed strong attachment of Fe onto the rGO surface. Energy-dispersive spectroscopy analysis validated the stoichiometric composition of the prepared Fe/rGO material. In conclusion, use of nZVI–rGO-activated SPC could represent an alternative technique for remediation of TCA-contaminated groundwater.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Chengfang Zhang,Jingchun Tang,Feilong Gao,Chen Yu,Song Li,Honghong Lyu,Hongwen Sun
The defects of easy agglomeration and oxidation of nano zero valent iron (nZVI) limit its large-scale application in industry, especially in the field of environmental remediation. In this study, the iron nanoparticles encapsulated by graphene nano-shells which anchored on the surface of carbon substrate (nZVI@gBC) were synthesized by a one-step carbothermal reduction method aided by Tetrahydrofuran. When the mass ratio of carbon source to iron source is 2:3 and the carbothermic reduction temperature is 700 °C, stabilized nZVI @gBC can be successfully synthesized with a high iron loading rate of 32.5%. The multilayer graphene shell can effectively prevent the rapid passivation and agglomeration of the nZVI core, and the electronic interaction between the iron nanoparticles core and the graphene carbon shell further enhances the catalytic activity and stability of nZVI@gBC. Therefore, due to the unique structure of graphene nano-shells, nZVI@gBC can be stably stored in the air for more than 80 days. In addition, nZVI@gBC exhibited superior catalytic activity in the experiment of removing 2,4-dichlorophenol (2,4-DCP) in groundwater as a persulfate activator. Notably, both the electron paramagnetic resonance (EPR) and quenching tests showed that SO 4 •− , •OH, O 2 •− and 1 O 2 were both involved in the degradation process of 2,4-DCP, and SO 4 •− were the major active species. Simultaneously, three possible degradation pathways of 2,4-DCP were deduced by GC/MS, which were caused by dechlorination, dehydrogenation or carbon–carbon bond cleavage under the attack of SO 4 •− , •OH, O 2 •− and 1 O 2 . Besides, nZVI@gBC can use the dissolved oxygen in the liquid to generate hydroxyl radicals to effectively remove 2,4-DCP without persulfate. This kind of multifunctional nZVI@gBC may become a promising iron-carbon catalyst for large-scale applications in the field of environmental remediation.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Siqi Zhang,Ziang Kong,Han Wang,Qun Yan,Dimitris V. Vayenas,Guangsheng Zhang
In this study, activated biochar (BC), nano zero-valent iron (nZVI) and biochar supported nano zero-valent iron (BC-nZVI) were used to remove cathodic nitrate in bioelectrochemical system (BES). With an initial NO 3 – -N concentration of 100 mg/L, it was found that the complete nitrate removal could be observed within 28 h for the group of BC-nZVI, whereas the accumulated ammonia reached 63.33 mg/L. Meanwhile, nitrate removal reaction rate constants reached 0.171, 0.110, 0.023 and only 0.010 h −1 for BC-nZVI, nZVI, BC and the Control groups, respectively. Besides, enzymatic activity of nicotinamide adenine dinucleotide (NADH) and nitrous oxide reductase (NOS) of the BC-nZVI group reached the peak faster than three other groups. As a carrier for nZVI, loading of nZVI onto BC could increase the surface area of BC-nZVI other than nZVI for microbial aggregation, while embedded nZVI would contribute to the granulation of sludge and nitrate reduction. Moreover, Cyclic Voltammetry (CV) and chronoamperometry (CA) indicated that BC-nZVI group obtain better electrochemical performances. Importantly, it was found that not only abundances of microbial genus, but relative abundances of those iron mediated enzymes responsible for electro-consuming, hydrogen production and preferential ammonia accumulated nitrate removal could all be enriched. Therefore, BC-nZVI could be implemented to enhance the nitrate removal at biocathode in BES.
研究领域:
环境工程
·
电化学
·
微生物学
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Jing Li,Mingjie Fan,Miao Li,Xiang Liu
The excellent potential of nanoscale zero-valent iron (nZVI) makes it a promising remedy for contaminated aquifers. More efficient remediation modes with nZVI have been investigated recently to overcome the inherent drawbacks of materials. In this study, a double surfactant-modified synthesis method is established to make the removal of Cr(VI) more efficiency. A specific focus of the materials status (suspension or powder) is devoted to explore the best application condition, especially for groundwater remediation . A non-ionic surfactant, polyvinylpyrrolidone (PVP), and an anionic surfactant, sodium oleate (NaOA), were selected to modify nZVI simultaneously. The kinetics and isotherm experiments, reactions at different pHs, initial concentrations, gas conditions, and coexisting ion conditions were conducted to analyse the removal mechanism. The characterizations before and after the reaction were used to further explain the results. From the batch experiments, a synergistic effect could be recognized in Cr(VI) elimination when PVP and NaOA were both used for nZVI modification. The materials in suspension (without drying process) exhibited higher removal efficiency in comparison with powder ones. These reactions happened in acidic condition demonstrated higher reactivity. The anaerobic condition facilitated the reaction, which showed prospect application in groundwater. Equilibrium could be reached within 2 min using the suspension sample with a removal efficiency above 99.5% and a maximum removal amount of 231.75 mg g −1 . The reaction process was well-fitted with pseudo-second-order kinetics and the Langmuir model. Cr(VI) was fully transformed into Cr(III), a safer status. These results show this is a promising in-situ method to eliminate Cr(VI) pollution in groundwater.
研究领域:
环境科学
·
水处理
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Environmental Research and Public Health
·
2022
·Vol. 19
·期 10
·6299
·
IF 4.614
Yue Lang,Yanan Yu,Hongtao Zou,Jiexu Ye,Shihan Zhang
Trichloroethylene (TCE) is one of the most widely distributed pollutants in groundwater and poses serious risks to the environment and human health. In this study, sulfidated nanoscale zero-valent iron (S-nZVI) materials with different Fe/S molar ratios were synthesized by one-step methods. These materials degraded TCE in groundwater and followed a pathway that did not involve the production of toxic byproducts such as dichloroethenes (DCEs) and vinyl chloride (VC). The effects of sulfur content on TCE dechlorination by S-nZVI were thoroughly investigated in terms of TCE-removal efficiency, H2evolution, and reaction rate. X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) characterizations confirmed Fe(0) levels in S-nZVI were larger than for zero-valent iron (nZVI). An Fe/S molar ratio of 10 provided the highest TCE-removal efficiencies. Compared with nZVI, the 24-h TCE removal efficiencies of S-nZVI (Fe/S = 10) increased from 30.2% to 92.6%, and the Fe(0) consumed during a side-reaction of H2evolution dropped from 77.0% to 12.8%. This indicated the incorporation of sulfur effectively inhibited H2evolution and allowed more Fe(0) to react with TCE. Moreover, the pseudo-first-order kinetic rate constants of S-nZVI materials increased by up to 485% compared to nZVI. In addition, a TCE degradation was proposed based on the variation of detected degradation products. Noting that acetylene, ethylene, and ethane were detected rather than DCEs and VC confirmed that TCE degradation followed β-elimination with acetylene as the intermediate. These results demonstrated that sulfide modification significantly enhanced nZVI performance for TCE degradation, minimized toxic-byproduct formation, and mitigated health risks. This work provides some insight into the remediation of chlorinated-organic-compound-contaminated groundwater and protection from secondary pollution during remediation by adjusting the degradation pathway.Keywords:S-nZVI;sulfidation;trichloroethylene;pathway;groundwater safety
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Shiyao Li,Rong Cheng,Jiahao Li,Haobo Hou,Yi Wang,Jiaao Chen,Yuwei Xiang,Min Zhou
The efficient removal of hexavalent chromium from solution is a challenging task, in this paper, the nZVI and nitrogen co-doped magnetic carbon aerogel microsphere composites (nZVI@NCAs) were prepared via the microemulsion polymerization and subsequent carbonization process, and were expected to satisfactory performance in the removal of Cr(VI). From batch experiments, the Cr(VI) removal process by nZVI@NCA900 fitted better with the pseudo-second-order model. The optimal nZVI@NCA900 was superior to that of most magnetic carbon-substrate composites, displaying high Cr(VI) adsorption capacity of 266.79 mg·g −1 at 318 K. Additionally, it was found that Cr(VI) was reduced to the low-toxicity Cr(III) from the results analyzed by XPS, and nZVI@NCA900 exhibited Cr(VI) reduction performance of 33.92% Cr(VI) reduced to Cr(III). The reaction between the nZVI@NCAs and Cr(VI) was pH-dependence, endothermic and spontaneous. Removal mechanisms might involve multiple processes. The nZVI particles on the surface acted as reductants to reduce Cr(VI) to Cr(III) and form Cr(III)/Fe(III) hydroxides to precipitate on nZVI@NCAs. Simulation results by DFT prove that N is an active site and show positive effect in the adsorption system. N atoms were used as active sites to stabilize the interaction with Cr(VI) via adsorption attributed to electrostatic and act as electron donors for reduction of Cr(VI). The nZVI particles encapsulated by carbon aerogels could provide magnetic stability after acid reaction, which was beneficial to the separation of adsorbents after reaction and reuse for many cycles. These results provide a new view for developing magnetic carbon materials to remove Cr(VI) from contaminated water.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 10
·2580
·
IF 5.076
Jien Ye,Yating Luo,Jiacong Sun,Jiyan Shi
The aggregation of nanoscale zero-valent iron (nZVI) particles and their limited transport ability in environmental media hinder their application in environmental remediation. In this study, the Cr(VI) removal efficiency, transport performance, and toxicity of nZVI and bentonite-modified nZVI (B-nZVI) were investigated. Compared with nZVI, B-nZVI improved the removal efficiency of Cr(VI) by 10%, and also significantly increased the transport in quartz sand and soil. Increasing the flow rate can enhance the transport of nZVI and B-nZVI in the quartz sand columns. The transport of the two materials in different soils was negatively correlated with the clay composition. Besides, modification of nZVI by bentonite could reduce toxicity to luminous bacteria (Photobacterium phosphereumT3) and ryegrass (Lolium perenneL.). Compared with Fe-EDTA, the transfer factors of nZVI and B-nZVI were 65.0% and 66.4% lower, respectively. This indicated that although iron nanoparticles accumulated in the roots of ryegrass, they were difficult to be transported to the shoots. The results of this study indicate that B-nZVI has a strong application potential in in situ environmental remediation.Keywords:nanoscale zerovalent iron (nZVI);hexavalent chromium;bentonite;toxicity
研究领域:
环境科学
·
化学
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
Processes
·
2024
·Vol. 12
·期 4
·697
·
IF 2.8
Fanbin Meng,Yuning Yang,Miao Li,Qizhi Zhu,Bing Qin,Chunpeng Yang
Aggregation and sharp reactivity decrease are the key problems of using nano zero-valent iron (nZVI) as a potential reaction medium for a permeable reactive barrier (PRB). In this study, nZVI particles encapsulated within an acrylonitrile–butadiene–styrene (ABS) matrix (nZVI/(ABS + EC)) was fabricated, which for the first time successfully simultaneously solved the above problems via accurately regulating the distribution of nZVI particles in the ABS matrix and regulating the contact between nZVI particles and the contaminated aqueous environment. In addition, the size and number of the pores throughout the ABS matrix were first regulated by ethyl cellulose (EC) for the purpose of controlling the contact between nZVI particles and the nitrate contaminant, affording apparent rate constants (kobs) for denitrification performance in the range of 0.0423 to 0.0820 min−1. The remediation of simulated nitrate-contaminated solution by nZVI/(ABS + EC) was suitably described by the first-order kinetics model, withkobsranging from 0.0423 to 0.2036 min−1, and functional relationship models ofkobswith the dosages of EC (dEC) and nZVI (dFe) during encapsulation were developed for the quantitative regulation of a sustainable denitrification performance. Results revealed that encapsulation prevents the aggregation of nZVI, rendering a sustainable denitrification performance of the material; the denitrification performance was demonstrated to be affected and quantitatively regulated by the encapsulation and application conditions. Using nZVI/(ABS + EC) as the reaction medium for PRB, the pore blocking of PRB can be avoided, and the sustainable remediation performance can be quantitatively regulated and predicted.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2014
·
IF 5.323
Yiming Su,Adeyemi S. Adeleye,Yuxiong Huang,Xiaoya Sun,Chaomeng Dai,Xuefei Zhou,Yalei Zhang,Arturo A. Keller
Nanoscale zerovalent iron (nZVI) has demonstrated high efficacy for treating nitrate or cadmium (Cd) contamination, but its efficiency for simultaneous removal of nitrate and Cd has not been investigated. This study evaluated the reactivity of nZVI to the co-contaminants and by-product formation, employed different catalysts to reduce nitrite yield from nitrate, and examined the transformation of nZVI after reaction. Nitrate reduction resulted in high solution pH, negatively charged surface of nZVI, formation of Fe 3 O 4 (a stable transformation of nZVI), and no release of ionic iron. Increased pH and negative charge contributed to significant increase in Cd(II) removal capacity (from 40 mg/g to 188 mg/g) with nitrate present. In addition, nitrate reduction by nZVI could be catalyzed by Cd(II): while 30% of nitrate was reduced by nZVI within 2 h in the absence of Cd(II), complete nitrate reduction was observed in the presence of 40 mg-Cd/L due to the formation of Cd islands (Cd(0) and CdO) on the nZVI particles. While nitrate was reduced mostly to ammonium when Cd(II) was not present or at Cd(II) concentrations ≥ 40 mg/L, up to 20% of the initial nitrate was reduced to nitrite at Cd(II) concentrations < 40 mg/L. Among nZVI particles doped with 1 wt. % Cu, Ag, or Au, nZVI deposited with 1 wt. % Au reduced nitrite yield to less than 3% of the initial nitrate, while maintaining a high Cd(II) removal capacity.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）